Re: [PATCH] Core driver for WM97xx touchscreens

Dmitry Torokhov
2008-01-18T17:23:55Z

Hi Mark,

On Fri, Jan 18, 2008 at 04:27:06PM +0000, Mark Brown wrote:
> This patch series adds support for the touchscreen controllers provided
> by Wolfson Microelectronics WM97xx series chips in both polled and
> streaming modes.
>

Thank you for the patches. Some comments below.

> +static int wm97xx_ts_input_open(struct input_dev *idev)
> +{
> + struct wm97xx *wm = (struct wm97xx *)input_get_drvdata(idev);

No need to cast.

> +
> + mutex_lock(&wm->ts_mutex);
> + /* first time opened ? */
> + if (wm->ts_use_count++ == 0) {

You do not need to implement a counter here. Input core makes sure
that open and close are only called for the fist and last user
respectivly. ts_mutex can go away as well.

> + /* set up touch configuration */
> + wm->input_dev->name = "wm97xx touchscreen";
> + wm->input_dev->open = wm97xx_ts_input_open;
> + wm->input_dev->close = wm97xx_ts_input_close;
> + set_bit(EV_ABS, wm->input_dev->evbit);
> + set_bit(ABS_X, wm->input_dev->absbit);
> + set_bit(ABS_Y, wm->input_dev->absbit);
> + set_bit(ABS_PRESSURE, wm->input_dev->absbit);
> + wm->input_dev->absmax[ABS_X] = abs_x[1];
> + wm->input_dev->absmax[ABS_Y] = abs_y[1];
> + wm->input_dev->absmax[ABS_PRESSURE] = abs_p[1];
> + wm->input_dev->absmin[ABS_X] = abs_x[0];
> + wm->input_dev->absmin[ABS_Y] = abs_y[0];
> + wm->input_dev->absmin[ABS_PRESSURE] = abs_p[0];
> + wm->input_dev->absfuzz[ABS_X] = abs_x[2];
> + wm->input_dev->absfuzz[ABS_Y] = abs_y[2];
> + wm->input_dev->absfuzz[ABS_PRESSURE] = abs_p[2];

input_set-abs_params(wm->input_dev, ABS_X, ...);
input_set-abs_params(wm->input_dev, ABS_Y, ...);
input_set-abs_params(wm->input_dev, ABS_X, ...);

I'd also recoomend using a temp for wm->input_dev, shoudl save a couple
of bytes.

> + input_set_drvdata(wm->input_dev, wm);

Also wm->input_dev->dev.parent = &dev; to put it in the proper place
in sysfs hierarchy.

> + ret = input_register_device(wm->input_dev);
> + if (ret < 0) {

Add input_free_device(); here.

> + kfree(wm);
> + return -ENOMEM;
> + }

I will need some more time to review and understand the need for the new bus
in the driver.

Thanks.

--
Dmitry